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1.
Clin Ophthalmol ; 18: 1667-1678, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38860118

RESUMEN

Purpose: Uncorrected refractive errors (REs) and amblyopia can lead to visual impairment with deleterious effects on quality of life and academic performance. Early detection and treatment by community vision care programs, such as the UCI EyeMobile for Children, can aid in addressing preventable vision loss. Methods: A total of 5074 children between the ages of 3 and 10 years were screened at 153 locations, including preschools, head start programs, and elementary schools within Orange County (OC), California (CA). Subsequently, 1024 children presented for comprehensive eye examinations. A retrospective analysis of all examined children was conducted, determining the frequency and severity of REs and amblyopia and the spectacle prescription rate by age. Propensity score matching analysis evaluated the effect of median household income on RE and amblyopia frequency. Results: Among those who failed initial screening and were subsequently examined, significant rates of REs and amblyopia were detected: myopia (24.4%), hyperopia (35.4%), astigmatism (71.8%), anisometropia (8.9%), amblyopia (7.0%), and amblyopia risk (14.4%). A majority (65.0%) of those examined received prescription spectacles from UCI EyeMobile, with around a third requiring a new or updated prescription. The frequency of REs and amblyopia and the spectacle prescription rate were uniform across OC congressional districts. Myopia and amblyopia risk was positively and negatively associated with household income, respectively. Conclusion: The UCI EyeMobile for Children serves as a vital vision care program, providing free vision screening, comprehensive eye examinations, and spectacles. A significant number of children required examination, and a high frequency of REs and amblyopia were detected in examined children, with subsequent provision of prescription spectacles to most children.

2.
Children (Basel) ; 11(5)2024 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-38790581

RESUMEN

Abusive head trauma (AHT) is an extreme form of physical child abuse, a subset of which is shaken baby syndrome (SBS). While traumatic injury in children is most readily observed as marks of contusion on the body, AHT/SBS may result in internal injuries that can put the life of the child in danger. One pivotal sign associated with AHT/SBS that cannot be spotted with the naked eye is retinal injury (RI), an early sign of which is retinal hemorrhage (RH) in cases with rupture of the retinal vasculature. If not addressed, RI can lead to irreversible outcomes, such as visual loss. It is widely assumed that the major cause of RI is acceleration-deceleration forces that are repeatedly imposed on the patient during abusive shaking. Still, due to the controversial nature of this type of injury, few investigations have ever sought to delve into its biomechanical and/or biochemical features using realistic models. As such, our knowledge regarding AHT-/SBS-induced RI is significantly lacking. In this mini-review, we aim to provide an up-to-date account of the traumatology of AHT-/SBS-induced RI, as well as its biomechanical and biochemical features, while focusing on some of the experimental models that have been developed in recent years for studying retinal hemorrhage in the context of AHT/SBS.

3.
Curr Opin Ophthalmol ; 35(4): 292-297, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38704713

RESUMEN

PURPOSE OF REVIEW: Pediatric refractive surgery has been growing at a steady pace since its introduction in the early 1980 s. This article will review common laser refractive surgeries performed on pediatric patients along with controversies regarding the practice. RECENT FINDINGS: Pediatric refractive surgery is reserved for a small population of children who fail amblyopic treatment due to high anisometropic refractive errors. Publications over the years have treated these children with various types of laser refractive surgery. SUMMARY: Laser pediatric refractive surgery appears to be well tolerated and effective for the population of children that need it. It provides an alternative for anisometropic amblyopia treatment for children who would have otherwise not been able to improve their vision.


Asunto(s)
Ambliopía , Procedimientos Quirúrgicos Refractivos , Humanos , Niño , Ambliopía/cirugía , Procedimientos Quirúrgicos Refractivos/métodos , Oftalmología/tendencias , Preescolar , Errores de Refracción , Anisometropía/cirugía
4.
BMC Ophthalmol ; 24(1): 179, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38641836

RESUMEN

BACKGROUND: Plusoptix photoscreeners are capable of measuring refractive errors of children from 1 meter distance, without cyloplegia. We aimed to compare refractive data obtained from the newest version of Plusoptix (model 12) with cycloplegic autorefraction. METHODS: We examined 111 consecutive children aged 3-7 years first by Plusoptix A12C under manifest condition and subsequently for cycloplegic refraction by Topcon KR-1 tabletop autorefractometer. Sphere, spherical equivalent, cylinder and axis of astigmatism measured by the two methods were analyzed to determine correlation, agreement and differences. RESULTS: Binocular examination of 111 children aged 4.86±1.27 years revealed good agreement between refractive data obtained by Plusoptix and cycloautorefraction, according to Bland-Altman plots. Significant (p < 0.001) and strong correlation was found between all refractive measurements (Pearson's r value of 0.707 for sphere, 0.756 for pherical equivalent, and 0.863 for cylinder). Plusoptix mean sphere, spherical equivalent and cylinder were 1.22, 0.56, and -1.32 D, respectively. Corresponding values for cycloautorefraction were 1.63, 1.00, and -1.26 D. The difference between axis of cylinder measured by the two methods was < 10° in 144 eyes (64.9%). CONCLUSIONS: Considering the significant agreement and correlation between Plusoptix photoscreener and cycloplegic autorefraction, the need for cycloplegic drops in refractive examination of children may be obviated. The mean difference between cylinder measurements are considerably trivial (0.06 D), but sphere is approximately 0.4 D underestimated by Plusoptix compared to cycloautorefraction, on average.


Asunto(s)
Astigmatismo , Errores de Refracción , Selección Visual , Niño , Humanos , Midriáticos , Selección Visual/métodos , Errores de Refracción/diagnóstico , Refracción Ocular
5.
J Pediatr Ophthalmol Strabismus ; : 1-8, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38661310

RESUMEN

PURPOSE: To analyze referral rates, patient demographics, referral indications, and the impact of socioeconomic factors on ocular health from the University of California Irvine (UCI) Eye Mobile for Children, particularly during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: A retrospective chart review was performed on de-identified records of children examined on the UCI Eye Mobile. GraphPad Prism 10.0.0 and Python software were used for statistical analyses. RESULTS: In the academic years from 2018 to 2022, 3,619 children received comprehensive eye examinations on the UCI Eye Mobile. Among them, 76 were referred to a pediatric ophthalmologist. The majority of these children were Hispanic (72.6%, 54 of 74), followed by Asian (10.9%, 8 of 74). A significant proportion (82.9%, 63 of 76) attended school districts with median incomes below that of Orange County. Statistically significant differences were found in age (P = .001; pre-COVID: 3.98 ± 1.08 years vs COVID: 5.75 ± 2.92 years) and gender (P = .023; pre-COVID female: 31 of 41 vs COVID female: 15 of 32) between the pre-COVID and COVID years. Additionally, there were significant differences in the proportion of children with hyperopia with astigmatism between the pre-COVID and COVID years (P = .044; pre-COVID: 23 of 40 vs COVID: 12 of 35). The most common indications for ophthalmologist referrals were for strabismus evaluation/treatment (28.9%, 22 of 76), followed by abnormal cup-to-disc ratio (21.1%, 16 of 76). CONCLUSIONS: The study highlights the pivotal role of the UCI Eye Mobile for children in identifying ocular conditions needing referrals to subspecialty care. The majority of children needing these referrals attended schools in lower economic communities. Additionally, the COVID-19 pandemic appears to have influenced the demographic and clinical characteristics. [J Pediatr Ophthalmol Strabismus. 20XX:X(X):XXX-XXX.].

7.
J. optom. (Internet) ; 17(1)Jan.-March. 2024. graf
Artículo en Inglés | IBECS | ID: ibc-229117

RESUMEN

Introduction A periodical self-monitoring of spherical refraction using smartphones may potentially allow a quicker intervention by eye care professionals to reduce myopia progression. Unfortunately, at low levels of myopia, the far point (FP) can be located far away from the eye which can make interactions with the device difficult. To partially remedy this issue, a novel method is proposed and tested wherein the longitudinal chromatic aberration (LCA) of blue light is leveraged to optically bring the FP closer to the eye. Methods Firstly, LCA was obtained by measuring spherical refraction subjectively using blue pixels in stimuli shown on organic light-emitting diode (OLED) screens and also grey stimuli with matching luminance. Secondly, the visual acuity (VA) measured with a smartphone located at 1.0 m and 1.5 m and displaying blue optotypes was compared with that obtained clinically standard measurements. Finally, the spherical over refraction obtained in blue light with a smartphone was compared with clinical over-refraction with black and white (B&W) optotypes placed at 6 m. Results Mean LCA of blue OLED smartphone screens was −0.67 ± 0.11 D. No significant differences (p > 0.05) were found between the VA measured with blue optotypes on a smartphone screen and an eye chart. Mean difference between spherical over-refraction measured subjectively by experienced subjects with smartphones and the one obtained clinically was 0.08 ± 0.34 D. Conclusions Smartphones using blue light can be used as a tool to detect changes in visual acuity and spherical refraction and facilitate monitoring of myopia progression. (AU)


Asunto(s)
Agudeza Visual , Refractometría/instrumentación , Teléfono Inteligente , Refracción Ocular , Rejas , Fotofobia , Pruebas de Percepción de Colores
8.
J Pediatr Ophthalmol Strabismus ; 61(2): 86-89, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37882183

RESUMEN

PURPOSE: To assess the responses of the ChatGPT-4, the forerunner artificial intelligence-based chatbot, to frequently asked questions regarding two common pediatric ophthalmologic disorders, amblyopia and childhood myopia. METHODS: Twenty-seven questions about amblyopia and 28 questions about childhood myopia were asked of the ChatGPT twice (totally 110 questions). The responses were evaluated by two pediatric ophthalmologists as acceptable, incomplete, or unacceptable. RESULTS: There was remarkable agreement (96.4%) between the two pediatric ophthalmologists on their assessment of the responses. Acceptable responses were provided by the ChatGPT to 93 of 110 (84.6%) questions in total (44 of 54 [81.5%] for amblyopia and 49 of 56 [87.5%] questions for childhood myopia). Seven of 54 (12.9%) responses to questions on amblyopia were graded as incomplete compared to 4 of 56 (7.1%) of questions on childhood myopia. The ChatGPT gave inappropriate responses to three questions about amblyopia (5.6%) and childhood myopia (5.4%). The most noticeable inappropriate responses were related to the definition of reverse amblyopia and the threshold of refractive error for prescription of spectacles to children with myopia. CONCLUSIONS: The ChatGPT has the potential to serve as an adjunct informational tool for pediatric ophthalmology patients and their caregivers by demonstrating a relatively good performance in answering 84.6% of the most frequently asked questions about amblyopia and childhood myopia. [J Pediatr Ophthalmol Strabismus. 2024;61(2):86-89.].


Asunto(s)
Ambliopía , Miopía , Oftalmólogos , Errores de Refracción , Humanos , Niño , Inteligencia Artificial , Ambliopía/diagnóstico , Ambliopía/terapia , Miopía/diagnóstico , Miopía/terapia
9.
J Optom ; 17(1): 100494, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37939574

RESUMEN

INTRODUCTION: A periodical self-monitoring of spherical refraction using smartphones may potentially allow a quicker intervention by eye care professionals to reduce myopia progression. Unfortunately, at low levels of myopia, the far point (FP) can be located far away from the eye which can make interactions with the device difficult. To partially remedy this issue, a novel method is proposed and tested wherein the longitudinal chromatic aberration (LCA) of blue light is leveraged to optically bring the FP closer to the eye. METHODS: Firstly, LCA was obtained by measuring spherical refraction subjectively using blue pixels in stimuli shown on organic light-emitting diode (OLED) screens and also grey stimuli with matching luminance. Secondly, the visual acuity (VA) measured with a smartphone located at 1.0 m and 1.5 m and displaying blue optotypes was compared with that obtained clinically standard measurements. Finally, the spherical over refraction obtained in blue light with a smartphone was compared with clinical over-refraction with black and white (B&W) optotypes placed at 6 m. RESULTS: Mean LCA of blue OLED smartphone screens was -0.67 ± 0.11 D. No significant differences (p > 0.05) were found between the VA measured with blue optotypes on a smartphone screen and an eye chart. Mean difference between spherical over-refraction measured subjectively by experienced subjects with smartphones and the one obtained clinically was 0.08 ± 0.34 D. CONCLUSIONS: Smartphones using blue light can be used as a tool to detect changes in visual acuity and spherical refraction and facilitate monitoring of myopia progression.


Asunto(s)
Miopía , Teléfono Inteligente , Humanos , Luz Azul , Refracción Ocular , Agudeza Visual , Miopía/diagnóstico
10.
J AAPOS ; 27(6): 374-376, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37863176

RESUMEN

Pyogenic granuloma, also known as lobular capillary hemangioma, is a benign vascular lesion that primarily affects the skin and mucous membranes. It is not pyogenic; nor is it granulomatous. It typically arises in response to local trauma or surgery, irritation, hormonal changes, or chronic inflammation, and it sometimes occurs spontaneously. The occurrence of pigmented pyogenic granuloma in the conjunctiva and cornea without any history of trauma or surgery is extremely rare, particularly in children. We report the clinical presentation, diagnostic evaluation, and successful management of bilateral biopsy-proven conjunctival and corneal pigmented isolated pyogenic granuloma in an 11-year-old girl. No signs of recurrence were seen at the 3-months follow-up.


Asunto(s)
Granuloma Piogénico , Niño , Femenino , Humanos , Granuloma Piogénico/diagnóstico , Granuloma Piogénico/cirugía , Granuloma Piogénico/patología , Piel/patología , Córnea/patología , Conjuntiva/patología , Inflamación
11.
Int J Mol Sci ; 24(20)2023 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-37894785

RESUMEN

Retinal hemorrhages in pediatric patients can be a diagnostic challenge for ophthalmologists. These hemorrhages can occur due to various underlying etiologies, including abusive head trauma, accidental trauma, and medical conditions. Accurate identification of the etiology is crucial for appropriate management and legal considerations. In recent years, deep learning techniques have shown promise in assisting healthcare professionals in making more accurate and timely diagnosis of a variety of disorders. We explore the potential of deep learning approaches for differentiating etiologies of pediatric retinal hemorrhages. Our study, which spanned multiple centers, analyzed 898 images, resulting in a final dataset of 597 retinal hemorrhage fundus photos categorized into medical (49.9%) and trauma (50.1%) etiologies. Deep learning models, specifically those based on ResNet and transformer architectures, were applied; FastViT-SA12, a hybrid transformer model, achieved the highest accuracy (90.55%) and area under the receiver operating characteristic curve (AUC) of 90.55%, while ResNet18 secured the highest sensitivity value (96.77%) on an independent test dataset. The study highlighted areas for optimization in artificial intelligence (AI) models specifically for pediatric retinal hemorrhages. While AI proves valuable in diagnosing these hemorrhages, the expertise of medical professionals remains irreplaceable. Collaborative efforts between AI specialists and pediatric ophthalmologists are crucial to fully harness AI's potential in diagnosing etiologies of pediatric retinal hemorrhages.


Asunto(s)
Aprendizaje Profundo , Hemorragia Retiniana , Humanos , Niño , Hemorragia Retiniana/diagnóstico , Hemorragia Retiniana/etiología , Inteligencia Artificial , Curva ROC , Fondo de Ojo
12.
J AAPOS ; 27(6): 354-357, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37741493

RESUMEN

Aplasia of the inferior rectus and inferior oblique muscles is extremely rare. Failure of the normal embryologic development of the inferior mesodermal complex can lead to agenesis of inferior rectus, inferior oblique, and lower sections of the lateral rectus muscles. This rare condition is usually seen in association with craniofacial syndromes or in conjunction with microcornea, microphthalmos, Axenfeld-Rieger syndrome, and coloboma. The usual treatment for this condition is a reverse Knapp procedure to improve the vertical alignment; however, this procedure can lead to complications, such as anterior segment ischemia, undercorrection, and torsional problems. To our knowledge, unilateral inferior rectus and inferior oblique muscle aplasia has not been described previously in a patient with congenital facial nerve palsy and optic nerve hypoplasia. In the present case, the patient was successfully treated with a modified minimally invasive horizontal rectus muscle transposition procedure.


Asunto(s)
Anomalías del Ojo , Síndrome de Goldenhar , Estrabismo , Humanos , Músculos Oculomotores , Síndrome de Goldenhar/complicaciones , Síndrome de Goldenhar/cirugía , Tenotomía/efectos adversos , Estrabismo/cirugía , Anomalías del Ojo/complicaciones , Anomalías del Ojo/cirugía , Procedimientos Quirúrgicos Oftalmológicos/efectos adversos
13.
Ophthalmology ; 2023 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-37656087
14.
J AAPOS ; 27(5): 267.e1-267.e7, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37722620

RESUMEN

PURPOSE: Neonatal retinal hemorrhage is a common finding in newborns, but the underlying mechanisms are not fully understood. A computational simulation was designed to study the events taking place in the eye and orbit when the head is compressed as the neonate passes through the birth canal. METHODS: A finite element model of the eye, optic nerve sheath, and orbit was simulated and subjected to forces mimicking rises in intracranial pressure (ICP) associated with maternal contractions during normal vaginal delivery. Resulting changes in intraocular pressure (IOP), pressure in the optic nerve sheath, and stress within the sclera and retina were measured. RESULTS: During contractions, increased ICP was transmitted to the orbit, globe, and optic nerve sheath. IOP rose by 2.71 kPa near the posterior pole. Pressure at the center of the optic nerve sheath rose by 7.31 kPa and up to 9.30 kPa at its interface with the sclera. Stress in the retina was highest near the optic disk and reached 10.93, 10.99, and 13.28 kPa in the preretinal, intraretinal, and subretinal layers, respectively. Stress in the sclera peaked at 12.76 kPa. CONCLUSIONS: Increasing ICP associated with natural vaginal delivery increases intraorbital pressure, which applies stress to the retina. Associated retinal deformation may cause tearing of the retinal vasculature. Increased pressure within the optic nerve sheath may occlude the central retinal vein, resulting in outflow obstruction and subsequent rupture. Forces accumulated near the optic disk, likely accounting for the tendency of neonatal retinal hemorrhage to occur posteriorly.


Asunto(s)
Disco Óptico , Hemorragia Retiniana , Femenino , Humanos , Recién Nacido , Hemorragia Retiniana/diagnóstico , Hemorragia Retiniana/etiología , Disco Óptico/fisiología , Retina , Presión Intraocular , Vasos Retinianos
16.
Clin Ophthalmol ; 16: 4249-4255, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36573233

RESUMEN

Purpose: To introduce the University of California Irvine (UCI) EyeMobile for Children preschool vision screening program and describe the ophthalmic examination results of children who failed screening with the PlusoptiX S12C photoscreener during one school year. Patients and Methods: Children aged 30-72 months were screened with the PlusoptiX using ROC mode 3 during the 2019-2020 school year. Children who failed screening were referred for comprehensive eye examination on the EyeMobile mobile clinic. Presence of amblyopia risk factors (ARFs), amblyopia, and refractive error was determined via retrospective review of records. Amblyopia was defined as unilateral if there was ≥ 2-line interocular difference in the best-corrected visual acuity (BCVA) and as bilateral if BCVA was < 20/50 for children < 4 years old and < 20/40 for children ≥ 4 years old. ARFs were defined using 2021 American Association for Pediatric Ophthalmology and Strabismus (AAPOS) instrument-based screening guidelines. Results: 5226 children were screened during the study period. Of the 546 children who failed screening, 350 (64%) obtained consent and were examined. Mean age of examined children was 4.45 years. Amblyopia was found in 8% of examined children, with unilateral amblyopia seen in 79% of amblyopic subjects. Glasses were prescribed to 246 (70.3%) children. Of the 240 children who received cycloplegic examinations, 43% had hyperopia and 30% had myopia. The positive predictive value (PPV) of the PlusoptiX screening for ARFs in children who received cycloplegic examinations was 70.4%. Conclusion: A significant proportion of Orange County preschoolers with refractive errors and amblyopia have unmet refractive correction needs. The PlusoptiX S12C photoscreener is an adequate screening device for the UCI EyeMobile for Children program, although modification of device referral criteria may lead to increased PPV. Further research is necessary to understand and overcome the barriers to childhood vision care in our community.

17.
Ophthalmol Sci ; 2(2): 100129, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36249696

RESUMEN

Purpose: Trauma to the eye resulting from a soccer ball is a common sports-related injury. Although the types of ocular pathologic features that result from impact have been documented, the underlying pathophysiologic mechanics are not as well studied. The purpose of this study was to evaluate the biomechanical events after the collision of a soccer ball with the eye to better understand the pathophysiology of observed ocular and retinal injuries and to compare them with those observed in abusive head trauma (AHT). Design: Computer simulation study. Participants: None. Methods: A finite element model of the eye was used to investigate the effects of a collision of a soccer ball on the eye. Main Outcome Measures: Intraocular pressure and stress. Results: Impact of the soccer ball with the eye generated a pressure wave that traveled through the vitreous, creating transient pockets of high and negative pressure. During the high-frequency phase, pressure in the vitreous near the posterior pole ranged from 39.6 to -30.9 kPa. Stress in ocular tissue was greatest near the point of contact, with a peak of 66.6 kPa. The retina experienced the greatest stress at the vasculature, especially at distal branches, where stress rose to 15.4 kPa. On average, retinal stress was greatest in the subretinal layer, but was highest in the preretinal layer when considering only vascular tissue. Conclusions: The high intraocular pressure and stress in ocular tissue near the point of soccer ball impact suggest that injuries to the anterior segment of the eye can be attributed to direct transmission of force from the ball. The subsequent propagation of a pressure wave may cause injuries to the posterior segment as the positive and negative pressures exert compressive and tractional forces on the retina. The linear movement of the pressure wave likely accounts for localization of retinal lesions to the posterior pole or superior temporal quadrant. The primarily linear force in soccer ball trauma is the probable cause for the more localized injury profile and lower retinal hemorrhage incidence compared with AHT, in which repetitive angular force is also at play.

18.
Diagnostics (Basel) ; 12(7)2022 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-35885436

RESUMEN

Soccer-related ocular injuries, especially retinal injuries, have attracted increasing attention. The mechanics of a flying soccer ball have induced abnormally higher retinal stresses and strains, and their correlation with retinal injuries has been characterized using the finite element (FE) method. However, FE simulations demand solid mechanical expertise and extensive computational time, both of which are difficult to adopt in clinical settings. This study proposes a framework that combines FE analysis with a machine learning (ML) approach for the fast prediction of retina mechanics. Different impact scenarios were simulated using the FE method to obtain the von Mises stress map and the maximum principal strain map in the posterior retina. These stress and strain patterns, along with their input parameters, were used to train and test a partial least squares regression (PLSR) model to predict the soccer-induced retina stress and strain in terms of distributions and peak magnitudes. The peak von Mises stress and maximum principal strain prediction errors were 3.03% and 9.94% for the frontal impact and were 9.08% and 16.40% for the diagonal impact, respectively. The average prediction error of von Mises stress and the maximum principal strain were 15.62% and 21.15% for frontal impacts and were 10.77% and 21.78% for diagonal impacts, respectively. This work provides a surrogate model of FE analysis for the fast prediction of the dynamic mechanics of the retina in response to the soccer impact, which could be further utilized for developing a diagnostic tool for soccer-related ocular trauma.

19.
Korean J Ophthalmol ; 36(3): 253-263, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35527527

RESUMEN

PURPOSE: Various types of trauma can cause retinal hemorrhages in children, including accidental and nonaccidental head trauma. We used animal eyes and a finite element model of the eye to examine stress patterns produced during purely linear and angular accelerations, along with stresses attained during simulated repetitive shaking of an infant. METHODS: Using sheep and primate eyes, sclerotomy windows were created by removing the sclera, choroid, and retinal pigment epithelium to expose the retina. A nanofiber square was glued to a 5 mm2 area of retina. The square was pulled and separated from vitreous while force was measured. A finite element model of the pediatric eye was used to computationally measure tension stresses during shaking. RESULTS: In both sheep and primate eyes, tension stress required for separation of retina from vitreous range from 1 to 5 kPa. Tension stress generated at the vitreoretinal interface predicted by the computer simulation ranged from 3 to 16 kPa during a cycle of shaking. Linear acceleration generated lower tension stress than angular acceleration. Angular acceleration generated maximal tension stress along the retinal vasculature. Linear acceleration produced more diffuse force distribution centered at the poster pole. CONCLUSIONS: The finite element model predicted that tension stress attained at the retina during forcible shaking of an eye can exceed the minimum threshold needed to produce vitreoretinal separation as measured in animal eyes. Furthermore, the results show that movements that involve significant angular acceleration produce strong stresses localized along the vasculature, whereas linear acceleration produces weaker, more diffuse stress centered towards the posterior pole of the eye.


Asunto(s)
Traumatismos Craneocerebrales , Hemorragia Retiniana , Animales , Niño , Simulación por Computador , Traumatismos Craneocerebrales/complicaciones , Análisis de Elementos Finitos , Humanos , Retina , Hemorragia Retiniana/diagnóstico , Hemorragia Retiniana/etiología , Ovinos
20.
Am J Ophthalmol ; 240: 58-66, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35247337

RESUMEN

PURPOSE: To study orthograde axonal transport with amyloid precursor protein (APP-A4) immunohistochemistry (IHC) in the retina and lamina cribrosa (LC) portion of the optic nerve in abusive head trauma (AHT) suspects. DESIGN: Retrospective, case-control study. METHODS: Seventy-two eyes from suspected AHT victims referred by the Los Angeles Coroner and control eyes from nontraumatized infants were included. IHC was conducted using University of California, Irvine (UCI), Lab Medicine Department's standard protocol and results analyzed by light microcopy after paraffin processing. Quantitation of LC APP-A4 block was estimated in 21 cases with known survival using MetaMorph, a proprietary biomicroscopy imaging software. RESULTS: The presence or absence of APP-A4 label accumulations in retinal ganglion cells, nerve fiber layer at the disc margin, and in LC axonal bundles were compared to matching tissues from nontraumatized control eyes with only background staining. Among the globes from AHT suspects with nerve heads available for study, 94% were positive for LC accumulation of marker. Among suspect AHT cases with known survival after injury of 1 to 1588 days, most demonstrated LC APP-A4 accumulations. CONCLUSIONS: Our findings reinforce a recent publication based on APP-A4 IHC that demonstrated similar orthograde axonal transport block in the LC in children with AHT and recommend that intraocular pressures be recorded and addressed in these patients.


Asunto(s)
Precursor de Proteína beta-Amiloide , Maltrato a los Niños , Traumatismos Craneocerebrales , Precursor de Proteína beta-Amiloide/metabolismo , Estudios de Casos y Controles , Niño , Maltrato a los Niños/diagnóstico , Traumatismos Craneocerebrales/diagnóstico , Humanos , Lactante , Células Ganglionares de la Retina , Estudios Retrospectivos
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